Revert "PCI/ASPM: Remove pcie_aspm_pm_state_change()"

This reverts commit 08d0cc5f34265d1a1e3031f319f594bd1970976c.

Michael reported that when attempting to resume from suspend to RAM on ASUS
mini PC PN51-BB757MDE1 (DMI model: MINIPC PN51-E1), 08d0cc5f3426
("PCI/ASPM: Remove pcie_aspm_pm_state_change()") caused a 12-second delay
with no output, followed by a reboot.

Workarounds include:

  - Reverting 08d0cc5f3426 ("PCI/ASPM: Remove pcie_aspm_pm_state_change()")
  - Booting with "pcie_aspm=off"
  - Booting with "pcie_aspm.policy=performance"
  - "echo 0 | sudo tee /sys/bus/pci/devices/0000:03:00.0/link/l1_aspm"
    before suspending
  - Connecting a USB flash drive

Link: https://lore.kernel.org/r/20240102232550.1751655-1-helgaas@kernel.org
Fixes: 08d0cc5f3426 ("PCI/ASPM: Remove pcie_aspm_pm_state_change()")
Reported-by: Michael Schaller <michael@5challer.de>
Link: https://lore.kernel.org/r/76c61361-b8b4-435f-a9f1-32b716763d62@5challer.de
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: <stable@vger.kernel.org>

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 55bc3576a98562807522e233223119f047822056..bdbf8a94b4d09fbc5d6593ab5c16bd91f748379f 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1335,6 +1335,9 @@ static int pci_set_full_power_state(struct pci_dev *dev)
                pci_restore_bars(dev);
        }
 
+       if (dev->bus->self)
+               pcie_aspm_pm_state_change(dev->bus->self);
+
        return 0;
 }
 
@@ -1429,6 +1432,9 @@ static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state)
                                     pci_power_name(dev->current_state),
                                     pci_power_name(state));
 
+       if (dev->bus->self)
+               pcie_aspm_pm_state_change(dev->bus->self);
+
        return 0;
 }
 

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 5ecbcf0411793e2242121d00ee776b3cd8f5d294..f43873049d52cf08e71fcf26e9dcc74afb7ef6d8 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -569,10 +569,12 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt);
 #ifdef CONFIG_PCIEASPM
 void pcie_aspm_init_link_state(struct pci_dev *pdev);
 void pcie_aspm_exit_link_state(struct pci_dev *pdev);
+void pcie_aspm_pm_state_change(struct pci_dev *pdev);
 void pcie_aspm_powersave_config_link(struct pci_dev *pdev);
 #else
 static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { }
 static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { }
+static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { }
 static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { }
 #endif
 

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 50b04ae5c394e3691d3b100eeed3918cd7be9f4c..8715e951c491943e9c39d94a6f3c3ecf4e8610e1 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1008,6 +1008,25 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev)
        up_read(&pci_bus_sem);
 }
 
+/* @pdev: the root port or switch downstream port */
+void pcie_aspm_pm_state_change(struct pci_dev *pdev)
+{
+       struct pcie_link_state *link = pdev->link_state;
+
+       if (aspm_disabled || !link)
+               return;
+       /*
+        * Devices changed PM state, we should recheck if latency
+        * meets all functions' requirement
+        */
+       down_read(&pci_bus_sem);
+       mutex_lock(&aspm_lock);
+       pcie_update_aspm_capable(link->root);
+       pcie_config_aspm_path(link);
+       mutex_unlock(&aspm_lock);
+       up_read(&pci_bus_sem);
+}
+
 void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
 {
        struct pcie_link_state *link = pdev->link_state;